DE102015205421A1 - Shutdown system for a drive train for a four-wheel drive of a motor vehicle - Google Patents

Abstract

The invention provides a shutdown system for a powertrain for a four-wheel drive of a motor vehicle. The shutdown system includes a first torque transmitting unit, a second torque transmitting unit and a clutch selectively activating the first torque transmitting unit and the second torque transmitting unit. The clutch has an engagement portion and an inner ring and an outer ring, which rings support the engagement portion. The inner ring is arranged such that it can be urged against the engagement portion to engage the clutch and move away from the engagement portion to release the clutch.

Description

The present application claims rights of U.S. Pat. Provisional Application No. 61 / 980,974, filed April 17, 2014, incorporated herein by reference.

The present disclosure relates primarily to automotive powertrains, and more particularly to automotive powertrain shutdown systems for four-wheel drives.

Background of the invention

Turning off a secondary axle in a four-wheel drive (AWD) vehicle can increase fuel efficiency. Known shutdown systems are normally arranged in an output unit (PTU) and require additional installation volume for installation in the vehicle. An arrangement of the Abschaltsystems within the void of a classic bevel gear differential allows easier installation in the motor vehicle.

U.S. Patent 7,975,796 . US Publication 2008/053780 . EP 2,181,011 . U.S. Patent 8,523,737 . U.S. Patent 8,382,633 and US Patent 2012/0202636 disclose systems for shutting off a secondary axle in a four-wheel drive vehicle.

Summary of the invention

The systems described in the above patent documents may all require too much installation volume and / or too much actuation energy. The present disclosure provides a shutdown system having a compact clutch with appropriate actuation energy.

The present invention provides a shutdown system for a powertrain for all-wheel drive of a motor vehicle. This shutdown system comprises a first torque transmitting unit, a second torque transmitting unit, and a clutch selectively activating the first torque transmitting unit and the second torque transmitting unit. The clutch has an engagement portion and an inner ring and an outer ring, which rings support the engagement portion. The inner ring is arranged so that it can be forced against the engagement portion to engage the clutch and move away from the engagement portion to disengage the clutch.

There is further provided a shutdown system for all-wheel drive of a motor vehicle according to a second embodiment of the invention. This shutdown system includes a first torque transmitting unit, a second torque transmitting unit, and a wedge clutch selectively activating the first torque transmitting unit and the second torque transmitting unit, and further comprising an electromagnet that can be controlled to selectively control the first torque transmitting unit and the second torque transmitting unit via the To effect wedge coupling.

The invention further provides a method of forming a shutdown system for a powertrain for all-wheel drive of a motor vehicle. The method includes providing an inner ring of a clutch on an intermediate shaft, providing an outer ring of the clutch on a differential, and providing an actuator on the intermediate shaft. The actuator may be operated to translate the inner ring in the axial direction for selective engagement of the clutch.

Brief description of the drawings

The present invention will be described below with reference to the accompanying drawings. The figures show:

1 a drive train of a four-wheel drive of a motor vehicle with a shutdown system, according to an embodiment of the present invention;

2 a cross-sectional view through a side view of a shutdown system according to an embodiment of the present invention;

3a and 3b Cross sections through side views of the in 1 shown shutdown system, which represent the engaged and disengaged positions of a clutch of the shutdown system, and

4 an exploded view of a cross section through a side view of the in 1 Shutdown system shown.

Detailed description of the drawings

The present disclosure provides a combination of an output shutdown device and a planetary differential. The shut-off clutch engages a spring, which spring biases a conical inner ring against a wedge clutch disc. An electromagnet pulls the inner ring away, so that the output unit comes off. The space occupied by the unit is the same size as a conventional bevel gear differential. It is possible, in alternative embodiments, to use other types of clutches (ie a dog clutch or a synchronous cone clutch) and / or other actuation methods (ie hydraulic, pneumatic, electromechanical).

1 shows a drive train 10 an all-wheel drive of a motor vehicle with a shutdown system 15 according to an embodiment of the present invention. The powertrain 10 has an engine 12 on top of a pair of front wheels 14 . 16 via a transmission unit 18 drives. The shutdown system 15 has a front differential 20 ( 2 ), between the transmission unit 18 and respective axes 22 . 24 the front wheels 14 . 16 is arranged to speed deviations between the front wheels 14 . 16 to take into account. An output unit 26 is with the front differential 20 connected to a rear wheel drive shaft 28 Drive via the respective rear axles 34 . 36 on the rear wheels 35 . 37 transferred to. The rear wheel drive shaft 28 is with a rear differential 30 connected, from which the rear axles 34 . 36 extend. The shutdown system 15 has a coupling 40 ( 2 ) on to the output unit 26 with the front differential 20 to connect, so that, under four-wheel drive conditions, the rear wheels 35 . 37 along with the front wheels 14 . 16 can be driven.

2 shows a shutdown system 15 , The shutdown system 15 has a coupling 40 for selectively activating a first torque transmitting unit 48 and a second torque transmitting unit 44 on. In this embodiment, the first torque transmitting unit 48 an input part in the form of a drive wheel designed to torque from the engine 12 to receive, and the second torque transmitting unit 44 is an intermediate shaft for the connection to the output unit 26 , The shutdown system 15 also has a wheel-side output shaft 42 on, which is designed so that it with the front wheel axle 22 can be connected. The output shaft 42 , which on a first axial side 50 of the system 15 is arranged, is part of the front differential 20 , which in this embodiment is a planetary differential and in one piece with a sun gear 46 is trained. The drive wheel 48 surrounds the output shaft 42 , A hub of the ring gear 48 supports a support bearing 51 of the differential at its outer radial surface. At a second, opposite the first page 50 lying axial side 52 indicates the planetary differential 20 a differential carrier 53 which has a second output shaft 54 surrounds. The second output shaft 54 which in one piece with a sun wheel 56 is formed, is designed such that it with the front wheel axle 24 can be connected.

An actuator 58 for the optional connection of the intermediate shaft 44 with the planetary differential 20 over the clutch 40 is pressed into the gearbox. The actuator 58 consists of one with a controller 62 equipped electromagnet 60 which control 62 the feeding of electric current into the electromagnet 60 regulated. Radial inside the actuator 58 and on a radially outer surface of the intermediate shaft 44 arranged rolling bearings 64 support the intermediate shaft 44 rotatable.

In this version is the clutch 40 designed as a wedge coupling and has an inner ring 66 , an outer ring 68 and an engaging portion in the form of a wedge disk 70 on which optionally between the inner and outer rings 66 . 68 can wedge. The inner ring 66 is so with an outer surface of the intermediate shaft 44 connected to it by splines grooved with the intermediate shaft 44 connected so that he together with the intermediate shaft 44 rotate and in the axial direction on the intermediate shaft 44 can slide. The outer ring 68 is by an axial projection 71 of the differential carrier 53 educated. At the lead 71 is the differential carrier 53 , regardless of the intermediate shaft 44 rotatable, by an on an outer radial surface of the electromagnet 60 arranged differential support bearing 72 supported. An elastic element 74 , which is formed in this embodiment in the form of a plate spring, is on the outer radial surface of the intermediate shaft 44 provided to the inner ring 66 in the axial direction of the electromagnet 60 away and to the planetary differential 20 to push.

The inner ring 66 has a tapered outer radial surface 76 on that with a tapered inner radial surface 78 the wedge disk 70 interacts. In this embodiment, both tapered surfaces are frusto-conical in order to be able to mate with each other. When the electromagnet 60 no power through the controller 62 receives, forces the diaphragm spring 74 the inner ring 66 against the wedge disk 70 with sufficient force, leaving the wedge disk 70 , due to the interaction of the tapered surfaces 76 . 78 , through the inner ring 66 radially outward against the outer ring 68 is pressed and the intermediate shaft 44 through the differential carrier 53 over the clutch 40 is driven in the circumferential direction. In this engaged state of the clutch 40 becomes the wedge disk 70 radially between the inner ring 66 and the outer ring 68 pressed together. With a current flow to the electromagnet 60 about the controller 62 becomes the inner ring 66 through the electromagnet 60 in the axial direction to the electromagnet 60 to and from the planetary differential 20 pulled away, leaving the electromagnet 60 the feather 74 Sufficiently compresses the radial decompression of the wedge disk 70 to effect. As a result of this radial decompression of the wedge disk 70 the clutch comes 40 in a dissolved state in which the differential carrier 53 turns without the intermediate shaft 44 To drive in the circumferential direction.

The 3a and 3b show cross sections through side views of the shutdown system 15 showing the engaged and disengaged positions of the clutch 40 represent. In 3a it is shown that the electromagnet 60 about the controller 62 cut off from the electricity, and the diaphragm spring 74 the inner ring 66 with a sufficient force against the wedge disk 70 that the inner ring 66 the wedge disk 70 against the outer ring 68 pushes, leaving the wedge disk 70 yourself between the inner ring 66 and the outer ring 68 wedged and torque from the differential 20 to the intermediate shaft 44 transfers. As in 3a shown is the inner ring 66 at a distance from the electromagnet 60 held. In 3b it is shown that the electromagnet 60 about the controller 62 is energized, and the magnetic forces of the electromagnet 60 overcome the forces of the plate spring 74 to the plate spring 74 squeeze and the inner ring 66 against an axial surface of the electromagnet 60 to draw. When pulling the inner ring 66 through the electromagnet 60 is the interaction between the tapered surfaces 76 . 78 minimized and the planetary differential 20 turns the intermediate shaft 44 over the clutch 40 Not. In an alternative embodiment may be on the spring 74 be dispensed with, and the electromagnet 60 can be designed such that it the inner ring 66 both in engagement with the wedge disk 70 brings as well as the inner ring out of engagement with the wedge disk 70 pull out.

4 shows an exploded view of a cross section through a side view of the Abschaltsystems 15 , In 4 is shown that the shutdown system 15 through two subunits 80 . 82 can be formed. The first subunit 80 is through the planetary differential 20 and the wedge disk 70 formed, and the second subunit 82 gets through the intermediate shaft 44 and the parts mounted thereon including the inner ring 66 , the plate spring 74 , and the camp 64 . 72 so that both subunits are parts of the coupling 40 exhibit. The wedge disk 70 can thereby with the planetary differential 20 be connected to that wedge disk 70 which is annular in a radially projecting lip 84 of the axial projection 71 locks. Accordingly, the shutdown system can 15 be formed by the subunits 80 . 82 be made separately, then the second subunit 82 such by axial sliding of the intermediate shaft 44 on the wave 52 axially to the first subunit 80 is mounted that the tapered surface 76 of the inner ring 66 radially inside the wedge disk 70 is recorded.

In the foregoing description, the invention has been explained with reference to certain exemplary embodiments and examples of the invention. It will, however, be evident that various modifications and changes may be made to the invention without departing from the broader spirit and scope of the invention as set forth below. Accordingly, the description and the drawings are to be considered as illustrative only and not in a restrictive sense.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7975796 [0004]
• US 2008/053780 [0004]
• EP 2181011 [0004]
• US 8523737 [0004]
• US 8382633 [0004]
• US 2012/0202636 [0004]

Claims (10)

Deployment system for a drive train for a four-wheel drive of a motor vehicle, comprising: a first torque transmitting unit; a second torque transmitting unit; a clutch selectively activating the first torque transmitting unit and the second torque transmitting unit, the clutch having an engagement portion and an inner ring and an outer ring, which rings support the engagement portion, and the inner ring is disposed so as to be urged against the engagement portion can be to engage the clutch and can be moved away from the engagement portion to release the clutch. The shutdown system of claim 1, further comprising an actuator for moving the inner ring in the axial direction to effect selectively activating the first torque transmitting unit and the second torque transmitting unit via the clutch. Shut-off system according to claim 2, wherein the actuator comprises an electromagnet, which moves in power supply, the inner ring in the axial direction of the engagement portion away to release the clutch. Shutdown system according to claim 3, wherein in a disengaged state of the clutch, the inner ring is held against the electromagnet, and in an engaged state of the clutch, the inner ring is held by the elastic member at a distance from the electromagnet. Shut-off system according to claim 2, further comprising an elastic member which is an elastic member which urges the inner ring against the engaging portion to engage the clutch, and the actuator causes the axial movement of the inner ring away from the engagement portion to the clutch to solve. Shutdown system according to claim 1, wherein the inner ring has a tapered outer surface, and wherein the engagement portion is radially compressed by the tapered outer surface when the inner ring is forced against the engagement portion to engage the clutch. The shutdown system according to claim 1, wherein the first torque transmitting unit is an input part configured to receive torque from the engine, and the second torque transmitting unit is a driven side shaft. A method of forming a shutdown system for a powertrain for all-wheel drive of a motor vehicle, comprising: the provision of an inner ring of a coupling on an intermediate shaft; the provision of an outer ring of the coupling to a differential, and the provision of an actuator on the intermediate shaft, wherein the actuator can be operated so that it can move for selective engagement of the clutch, the inner ring in the axial direction. The method of claim 8, wherein the actuator comprises an electromagnet. The method of claim 9, wherein the coupling is a wedge coupling having a wedge disk radially disposed between the inner ring and the outer ring, the inner ring having a tapered outer surface, and the wedge disk compressed by the tapered outer surface in the radial direction is, if, in order to engage the clutch, an elastic element, the inner ring wedges against the wedge disk.

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